Vat dyestuffs



United States a atent VAT DYESTUFFS No Drawing. Original application Jan. 26, 1955, Ser. No. 484,296, now Patent No. 2,882,272, dated Apr, 14, 1959; Divided and this application Aug. 14, 1958, Ser. No. 758,642

Claims priority, application Germany Feb. 4, 1954 '3 Claims. (Cl. 260-275) The present invention relates to new vat dyestuffs of the benzanthrone-pyrazoleanthrone series; more particularly it relates to dyestuffs corresponding to the general formula:

wherein one R represents a lower alkyl group and the other R represents hydrogen, X stands for hydrogen or chlorine, Y stands for hydrogen, chlorine or bromine and n means a numeral ranging from 0.5 to 2.

This application is a division of Schlichenmaier et al. application Serial Number 484,296, filed January 26, 1955, and now US. Patent No. 2,882,272.

In German Patent No. 490,723 is described inter alia a process for the manufacture of a blue vat dyestuif, the B2 2 phenyl benzanthrone pyrazoleanthrone. Corresponding dyestuffs containing an alkyl group in the B2- nucleus have hitherto not been disclosed in literature.

Now we have found that vat dyestuffs of the benzanthrone-pyrazoleanthrone series containing an alkyl group in the Bz-nucleus. can be obtained by melting N(l)-(Bz- 1'-benzanthronyl)-pyrazoleanthrones containing an alkyl group in the Bz-nucleus in known manner with alkaline.

condensing agents and, if desired, treating the dyestuifs so obtained with halogenating agents.

The new dyestuffs yield on cotton or viscose rayon violet to blue dyeings which are distinguished by a very good fastness to chlorine and good general fastness prop erties.

The N( l (BZ-1-benzanthronyl) -pyrazole-anthrones containing an alkyl group in the Bz-nucleus which are used as parent materials can be obtained by condensing, at a raised temperature, preferably at a temperature of about 120-150 C., pyrazole-anthrones with Bz-lchloro-Bz-alkylbenzanthrones in alkylformamides in the presence of acid-binding agents.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto; the parts being by weight:

Example 1 20 parts of N(1)-(Bz-1'-(Bz-2'-ethyl)-benzanthronyl)- pyrazole-anthrone melting at 363 C., which is obtainable by reacting pyrazole-anthrone with Bz-l-chlo'ro-Bz- 2-ethylbenzanthrone in dimethylformamide at a raised temperature in the presence of potassium carbonate, are introduced at C. into a melt of 25 parts of caustic potash and 30 parts of ethanolamine, and the mixture is stirred for one hour at this temperature. The melt is then poured into a mixture of 150 parts of ice and 150 parts of water, while blowing air into the reaction mixture until oxidation of the leuco compound of the dyestuff is complete. The dyestuff is then filtered off, washed while hot until a neutral reaction is obtained, dried and recrystallized from concentrated sulfuric acid. The dyestuti so purified dyes cotton from a blue vat reddish blue tints of good wet fastness properties and a very good fastness to chlorine and to light. It corresponds to the following formula:

Example 2 Example 3 When in Example 1 the Bz-Z-ethyl-benzanthronyl-pyrazoleanthrone is replaced by 20 parts of N(1)-(Bzl'-(Bz- 2'-methyl)-benzanthronyl)-pyrazoleanthrone melting at 374 C., a dyestuff is obtained which dyes cotton from a blue vat bluish-violet tints of good fastness properties, especially a good fastness to chlorine.

Example 4 A solution of 1.2 parts of sodium chlorate in parts of water is added dropwise, while stirring, within 3 hours,

at 20 C. to a suspension of 'parts of the dyestufi described in Example 1 in the form of a paste of percent strength in 50 parts of water and 100 parts of concentrated hydrochloric acid. The reaction mixture is then filtered off, washed until neutral and standardized to a paste of 10 percent strength. The new dyestuff so obtained which contains about 1 chlorine atom per dyestuff molecule dyes cotton slightly greener tints than that described in Example 1 and is distinguished by good fastness properties, especially by a good fastness to chlorine.

If the chlorination is carried out ata temperature of 80 C. instead of at 20 C., a dyestuif is obtained which contains about 2 chlorine atoms per molecule. It dyes cotton somewhat greener tints and has the same fastness properties. i

Example 5 The dyestuff described in Example 2 is chlorinated at 20 C. with sodium chlorate and hydrochloric acid as described in Example 4. A new dyestufl is obtained which contains a further /2 chlorine atom per molecule and dyes cotton somewhat greener tints than the original dyestuff. The fastness properties, especially its fastness to chlorine, are good.

Example 6 If the dyestuff described in Example 3 is chlorinated at 20 C with sodium chlorate and hydrochloric acid as described in Example 4, a product is obtained which contains about 0.7 chlorine atom per molecule. The new dyestufi yields considerably greener dyeings than the product which is free from chlorine. The fastness properties are good.

Example 7 4 parts of the dyestufi described in Example 3 are dissolved at the boil in 40 parts of nitrobenzene. The solution'is cooled to 70 C. and, after the addition of 0.1 part of iodine, 4 parts of sulfuryl chloride are added dropwise within 1 /2 hours. The reaction mixture is stirred for 4 hours at 70 C. and is then allowed to stand overnight. The .dyestuff which has separated in the form of crystals is then filtered off, washed with nitrobenzene and alcohol, and dried. It contains about 2 chlorine atoms per dyestutf molecule and dyes cotton considerably greener tints than the non-chlorinated dyestuff. Its fastness properties, especially its fastness to chlorine, are good.

Example 8 When in Example 2 the Bz-2-ethylbenzanthronylpyrazoleanthrone is replaced by 20 parts of N(1)-(Bz-l- (Bz-2'-isopropyl)-benzathronyl) pyrazoleanthrone melting at 351 C., which is obtainable by reacting pyrazoleanthrone with BZ-1-chloro-Bz-2-isopropyl-benzanthrone in dimethylformamide at boiling temperature in the presence of potassium carbonate, a dyestuff is obtained which dyes cotton from a blue vat clear greenish-blue tints of good fastness properties, especially of a good fastness to chlorine. 1

Example 9 4 parts of the dyestutf described in Example 8 are dissolved in 80 parts of nitrobenzene, 0.1 part of iodine is then added to the solution as a catalyst and 4 part-s of sulfuryl chloride are added dropwise, within one hour, at 70 C., and the reaction mixture is stirred for further 4 hours at that temperature. After cooling, the dyestuff is filtered off, washed with nitrobenzene and methanol and dried. The dyestuff so obtained contains about 2 chlorine atoms per dyestufi molecule. It dyes cotton from a clear blue vat clear reddish-blue tints. Its fastness properties, especially its fastness to chlorine, are good.

The dyestufi corresponds to the following formula:

CH5 CHa Example 10 EXAMPLE 11 When in Example 1 the Bz-2-ethyl-benzanthronyl-p'yrazoleanthrone is replaced by 20 parts of N(1)-Bz-1- (Bz-3-methyl)-benzanth1'onyl)-pyrazoleanthrone, which forms yellow crystals melting at about 320 C., and the reaction product is worked up as described in Example 1, a dyestufl is obtained which dyes cotton from a clear blue vat considerably more reddish blue tints than the dyestuif described in Example 8. The dyestulf is distinguished by a good fastness to washing.

Example 12 4 parts of the dyestufi described in Example 11 are dissolved, while stirring, in 70 parts of chlorosulfonic acid and 0.1 part of iodine is added to the solution. After heating to 50 C., 2 parts of bromine dissolved in 10 parts of chlorosulfonic acid are introduced dropwise at 4050 C. within 5 hours. tion is then cooled to about 5-10 C. and diluted at that temperature with 78 parts of sulfuric acid of 50 percent strength, while stirring. The crystals which have v separated are filtered off with suction, washed first with sulfuric acid of 80 percent strength and then with water until neutral. The dyestufl so obtained contains about 1.5 bromine atoms per molecule; it dyes cotton from a clear blue vat somewhat greener tints than the dyestutf described in Example 11 and is distinguished by a good fastness to Washing.

We claim: 1. A vat dyestuff corresponding to the general formula The clear violet soluwherein X stands for a member selected from the group consisting of hydrogen and chlorine, Y stands for a member selected from the group consisting of hydrogen, chlorine and bromine, and n means a numeral ranging from 0.5-2.

2. The dyestufi corresponding to the following formulazz 3. The dyestufi corresponding to the following formula:

References Cited in the file of this patent UNITED STATES PATENTS 1,790,780 WiIke Feb. 3, 1931 2,647,899 Randall Aug. 4, 1953 FOREIGN PATENTS 295,397 Switzerland Mar. 1, 1954 

1. A VAT DYESTUFF CORRESPONDING TO THE GENERAL FORMULA 